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Trash star 13 EP

HD 69531

RA 124.2200° · Dec -16.2376° · star

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Score breakdown

· 3 badges
13 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 13

2 more points to reach Common.

Badges

  • Star · +3
  • White A-type star · +5
  • Subgiant (leaving the main sequence) · +5

Trivia

Hard to believe

  • True brightness. It pours out about 2.2 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

  • Spectral class. Its spectrum reads A0IV — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

Find it in the sky

  • How to spot it. At magnitude 9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Puppis.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around January — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out brilliant white (B−V 0) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

Properties

absmag
-11.01
bv
0
constellation
Pup
luminosity
2208004.733
mag
8.99
name
HD 69531
spect
A0IV

About HD 69531

HD 69531 is a trash star. It sits in the constellation Pup, shines at apparent magnitude 8.99 and has spectral type A0IV.

Its spectrum reads A0IV — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 69531 in the constellation Pup. At apparent magnitude 8.99, it is an easy target for binoculars.

Like any astronomical target, HD 69531 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why HD 69531 is a trash star

HD 69531 scores 13 points on Spacedle's rarity scale, which places it in the trash tier. Another 2 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, White A-type star and Subgiant (leaving the main sequence) — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.